Consequently, since the Malkhut of the level ascended to the Bina in that same level, the Malkhut arrested the light in the place to which it ascended, that is, in the middle of Bina.25This ascent of Malkhut to Bina is referred to as the second constriction, and is referred to in Petiḥa LeḤokhmat HaKabbala, sections 57 – 58. The half of Bina, and Tiferet and Malkhut, which are situated under the terminating Malkhut, which is now situated in Bina, left their original level and became a separate, second level under Malkhut.
Thus, on account of the ascent of Malkhut to Bina, each level has been divided in half, so that Keter, Ḥokhma, and half of Bina, which are above Malkhut, remained in the level, while half of Bina, Tiferet (which contains Ḥesed, Gevura, Tiferet, Netzaḥ, Hod, and Yesod), and Malkhut left the level and became the level below it. This blockage performed by Malkhut in the middle of Bina is called a diaphragm. Keep this in mind.